146 DISTRIBUTION OF EXTINCT ANIMALS. [part ii. 



large size, especially among the Edentata and American families 

 of Kodents, are additional proofs of a very high antiquity. 

 Yet many of these cave animals are closely allied to those 

 which are found in North America in the Post-Pliocene deposits 

 only, so that we have no reason to suppose the cave-fauna to 

 be of much earlier date. But the great amount of organic 

 change it implies, must give us an enlarged idea of the vast 

 periods of time, as measured by years, which are included in 

 this, the most recent of all geological epochs. 



Pliocene Period of Temperate South America. — We have now 

 to consider the numerous remains of extinct animals found in 

 various deposits in the Pampas, and in Patagonia, and a few in 

 Bolivia. The age of these is uncertain; but as they are very 

 similar to the cave-fauna, though containing a somewhat larger 

 proportion of extinct genera and some very remarkable new 

 forms, they cannot be very much older, and are perhaps best 

 referred at present to the newer portion of the Pliocene 

 formation. 



Carnivora. — The genus Machairodus or sabre-toothed tigers, 

 represents the Felidae. There are several species of wolves 

 (Canis) ; a weasel (Mustela) ; two bears of the Brazilian cave- 

 genus Arctotherium; and the extinct European genus Hyamarctos. 



Ungulata. — There are two species of Eqnus, found in the 

 Pampas, Chili, and Bolivia; two of Macrauchenia, an extra- 

 ordinary extinct group allied to the tapir and Palceothcrium, but 

 with the long neck, and general size of a camel. A second 

 species found on the highlands of Bolivia is much smaller. 



A more recent discovery, in Patagonia, is the almost perfect 

 series of teeth of a large animal named Homalodontotherium; and 

 which is believed by Professor Flower, who has described it, to 

 have been allied to Rhinoceros, and still more to the Miocene 

 Hyracodon from North America ; and also to present some 

 resemblances to Macrauchenia, and though much more remotely, 

 to the curious genus Nesodon mentioned further on. 



The Artiodactyla, or even-toed Ungulates, are represented by a 

 species of Picotyles, or peccary, found in the deposits of the 



